With respect to photosensitive materials which lose the qualitative values by exposing them to light, known packaging bags can shield light completely. In such cases, the package is required to have not only complete light-shielding properties, but also freeness from ill effects on photographic performance, various physical strength (bursting strength, tear strength, impact puncture strength, Gelbo test strength, tensile strength, and the like), and have excellent heat sealing properties (heat-sealing strength, sealing properties against foreign matter, hot sealing strength or chronological heat sealing strength, and the like), anti-static properties, amenability to recycling, amenability to incineration, and the like. The following techniques, for example, have so far been disclosed for meeting these characteristics.
A film for packaging a photosensitive material having at least one layer of a light-shielding film comprised of a polyethylene based polymer and not less than 1 wt % of a light-shielding material, with not less than 50 wt % of the total polyethylene based polymer being linear low-density polyethylene (JP Patent Kokoku JP-B-2-2700). A packaging material for a photosensitive material comprised of a layered material made up of a substrate and a polyethylene based polymer layer formed on at least one surface of the substrate, in which the polyethylene based polymer layer is formed of not less than 50 wt % of linear low density polyethylene substantially free of a light shielding material and in which the layered material has a light-shielding layer sufficient for light shielding (JP Patent Kokoku JP-B-2-2701). An easy-to-open packaging material for a photosensitive material comprised of an inner light-shielding heat-sealable film layer containing a lubricant, a light-shielding material and not less than 50 wt % of the high-pressure low-density polyethylene resin, an aluminum foil layer layered on the light-shielding heat-sealable film layer, with a peeling strength of 400 g/15 mm width or more and having an anchor coating layer towards the light-shielding heat-sealable film layer, and a heat-resistant flexible sheet layer layered on the aluminum foil layer and having heat resistant properties of not less than 5.degree. C. with respect to the light-shielding heat-sealable film layer (JP Utility Model Kokoku JP-B-2-19226).